Hide treatment



Patented Nov. 14, 1944 Victor Conquest, Chicago,- and Havard L. Keil, Clarendon Hills, 111., assiznors to Armour and Company, Chicago, a corporation of Illinois No Drawing. Application April 23, 1942,

. Serial No. 440,252 1 19 Claims.

This invention is concerned with processes for the recovery of hair and proteinaceous materials rom hides and skins and particularly with such processes wherein thehides and skins are treated with stomach linings. l l

Attempts have been made heretofore to re cover wool and hair from hides and'hide scraps by the use of pepsin but it has been found all the pepsin compositionshitherto used have been unsatisfactory. Pepsin compositions which have been known in the past have failed to attack and solubilize all of the hide constituents with the result that the recovery of'wool and hair has been incomplete and the material so recovered has been contaminated with hide residues. It

layer of skin is practically unattaeked by a pep.

sin digestion.

We havenow discovered that the hide constituents are digested or disintegrated so that they'becom soluble and the hair can be separated therefromby treatingzhair-bearing hides with stomach lining, or fundus, which contains peptic and lypolytic enzymes. The stomach linings which are effective in this process are those from hogs, sheep, cattle or other animals in which peptic enzymes are elaboratedin the stomach.

has been foundparticularly that the epidermal ing-helps to break up a protein-lipoid complex and thus acts to disintegrate the hide and free the hair. .Whatever the mechanism of this reaction, treating with, the stomach linings makes possible, the disintegration of the hide material and the recovery of-the hair in an undamaged. state and of proteinaceous materials which are useful in glue manufacture and thelike.

In carrying out our process the hides and skins are treated in the presence of water with linings,

of stomachs from animals such as hog, sheep or cattle at a pH of from about 1.0 to about 2:5. This treatment may advantageously be carried out .at a temperature of from about 100 F. to about 115 F. Ifthe hide material has been subjected to the treatment with the stomach linings Itis-an advantage of our process that the pro-.

tein degradation products which are recovered in the liquid solution are good-starting materials for the manufacture of glue and other useful products. l

It is an-important advantage of our process also that hides and skins which have been .treat-,,

ed in this manner yield wool or hair which is quite free of fatty material and requires less drastic scouring than the usual product.

It is a further advantage of our process that hide scrap and skin scrap, which are in fairly small pieces and are diflicultto handle, may be treated in this way to produce wool or hair in good yield as well as valuable proteinaceous liquors;

act are also effective in preventing the growth of undesirable organisms :and thus prevent putrefactionsof the masabeing treated. There are several active constituents present in stomach linings, including peptic enzymes and lipase." It'may be'that the lipase exerts its ac-,

It'isalso an advantage of our process that. the conditions under which the stomach linings tion upon the lipoidal constituents of the hide or skin material and permits the peptic enzymes to infiltrate and attack the proteinaceous constituents. It may also be that the combined action of the active principles of the stomach 111 so that part of the hide goes into solution but the hide has not been completely'digested and disintegrated thereby, it may be neutralized and heated to a higher temperature to destroy the'en-. zymes and to break down and disintegrate the remaining gelatinous hide material. l

The liquid portion of the digest which is pre-- pared according to our invention may be a solutionin the strict sense of the term or it may v contain-finely divided particles of hide material,

in suspension, but for convenience it is referred toin this specification and inthe-appendedclaims as a solution. At the end of the treatment the solution is separated from the hair, carrying with it all of the hide-constituents and leaving the hair free of hide or skin material, the liquid containing the proteinaceous substanceswhich may then be worked up for other purposes. r 1

The following examples will demonstrate more specifically certain methods of carrying out our process.

g Y Example I 300 lbs. of sheep hide scrap are washed and placed in a vat with enough water to cover them. There are then added v2 7 lbs. of muriatic acid (24% hydrochloric acid) and 9 lbs. of fresh hog stomach. Themass is heated at from F. to l10 -'F, for, about 48 hours- The mixture has a pH of about 1.25 when the acid has been added and increases to pH 1.9 by the end of 48 hours. At the end of the digestion period, the mixture is neutralized by adding sodium carbonate and is then heated to boiling. The heating step destroys any residual enzymes and also brings into solution any remaining pieces of partially disintegrated hide.

The liquid containin the protein breakdown products and the fatty materialls drained of! soapy mixture is, heated .to boilingand, after a, short period. the soapyj emulsion containing'fatty' or greasy impurities is drained oil? and the wool is then well rinsed with hot water.

Example II 300 lbs. of sheepskin trimmingsv whichhave been treated with sulfide to remove the greater part of the wool are placed inia vat'and covered with water.

There are then" added 15 lbs. of muriatic acid (24% hydroehloric 'acidl which:

brings the mixture to pH 1.7 and th acidified mass is allowed to stand for 24 hours with occasional stirring. At the end of this time it is pounds.

The hide pieces are thenv covered with water,

linings from the remainder of the stomach material. The stomach or stomach linings used in the process may be fresh stock or may be material which has been frozen for purposes of preservation during storage or transportation, or may be material which has been dried or treated in any other way as long as the desired physiological characteristics have not been destroyed. The hides when treated at from 100 F. to 115 F. are suitably held for 36 hours .or more. "However, the time of holding will be shortened when the temperature employed is higher; and it will be lengthened when th temperature is lower. The-time will also vary somewhat with the size of the hide pieces which are being treated,"s'maller'scrap being more quickly dirgested.

It-has been found in the past that wool recovered from sheep hide or scrap is quite greasy and and hydrochioric acid'is added to bring. the mix 'ture to a-pH of 1-.5.- There are then added 9lbs. 25

oi hog stomach-' linings and the temperature ofthe 'mass-is raised-to 102 Fpand maintainedat that point for36 hours. At' the end of this'dige's: tion-period the mixture'ls adjusted: to pH 8.0'and rinsed with hot water.- It=is then scoured by is heated to 'boiling'. "After a'short 'periodof boil--v -ing, the solution is drained oi! and-the wool-is heating with water containing about 3 lbs. of 1 sodium carbonateand 3 lbs. of soap chips, after which the; woolisseparated from" the liquid and dried. a

The. jtempe rature of digestion ofthe-hide material should-=be-sornewhat elevated-but shouldnot'exceedj' of course, thetemperature at which "min which peptic enzymes are normally elaborated,

the" enzymes are inactivated by'heat. The diges-= tlon" is'preferably carried on-at a temperatm-e of from about .100 "F.'to 115*1-. At 'a-lower:tem-' perature the digestion" proceeds somewhat more slowly and requires a longer-time to cause disintegration of-th'e hide materiahwhile at higher temperatures,- not exceeding the destructive temast re; the digestion" proceeds =more. rapidly. The destructive temperatureswill be found'tobe of the order 01-1300 F;- v

h w k ng wiui hides or skins which have e n treatedwith' sulfides and limes, we have found itadvisableto -pre-treat the hides or skins torem'ove the added compoundspresent thereon.

This is suitably done by soaking ontreating the material with acidified water, the mixture having ap'I-I'of 6 .00 or below-and advantageously a pH of from about 1.0 to about 3.0, to ,leach out theundesirable substances. -,The,soaking operation is preferably carried out at a temperature of from about 100 F,- to about1 15'F. The hides are then drained free or the leaching solutioii and'after ward are treated'with the stomachmaterial ashe'retofore described.'

The hide or -:skin oi' any typeofanir'nal can be treated by our process.) Thus We} can recover bristles from "pigskin, wool frojmsheepskin, hair: from cattle' hide' and, simultaneously from' any or these, valuable proteinaceous solutions.

In carrying out our invention we can use thewholeanimal stomach, or we can separate the' lining from the remainder 'of'the stomach and use just the lining. In either 'mode' or practice the hide is subjected tothe action of the enzymes contained in the lining portion. inmostinstances we find no necessit'y'ffor separating the;

taminated with much less fat and thescouring operation is greatly simplified.

The above specific description is given for purposes of illustration only audit is to be understood that I many modifications and variations may be made therein without departing from the spirit and scope of-this invention.

Weclaim: I I =1..A process for treatinghide to recover hair therefrom whichcomprises subjecting said hide to the action of the lining of an animal stomach inwhich peptic enzymes are normally elaborated, inthe presence of water at a pH of from about -1.0 to about 2.5 ,until' hid is brought into solution, and recovering hair from said solution.

2. A process. for treating hide to recover hair therefrom which comprises subjecting said hide".

to the action of thelining of-an animal stomach in the presence of water-at a pH of fromabout 1.0 .to about 2.5, for at least 36 hours, neutralizing the-resulting mixtureyheatingsaid mixture to boiling. and'removing hair from the resulting .vliquid.

.3; Aprocess for treating sheep scrap to recover wool therefrom which comprises subjecting said of the scrap-has gone into solution, neutralizing the resulting mixture, heating to destroy the enzyme and bringall of the'scrap into solution,"

"and recovering the wool from said solution.

"4. -A.process for treating hide to recover hair.

therefrom which-comprises subjecting said hide to the action ofthe-lining of an animal stomach in which pepticenzymesare normally elaborated,

' in thepresence of water at a pH of from about 1.0 v

to about 2.5, at a temperature of from about F. to about F., until the hide .is disintegrated,

and recovering the hair from theresulting solu-' I tion.- 1

' 5. 'Aiprocess' for treating hide to recover hairv therefrom which comprises subjecting said hide to the action of the liningrof-an animal stomach in which peptic enzymesare normally elaborated, in the presence of water at a pH of from about 1.0

to-about 2.5,.at a temperature'of from about 100 F. to about 115 F., until at least part of the hide has gone'into solution, neutralizing the resulting mixture, heating to destroy the enzyme and bring the remaining hide material covering the hair. I

into solution, and re- 6. A process for treating hide containing sulfide to recover hair therefrom which comprises treating said hide with water at a pH of less than about 6.0 to leach out the sulfide, separating,

the hide from said leaching water, subjecting the treated hide to the action of th lining of an animal stomach in which peptic enzymes are normally elaborated, in the presence of water at a pH of from about 1.0 to about 2.5, until the hide is brought into solution, and recovering hair from said solution.

7. A process for treating hide containing sulfide to recover hair therefrom which comprises treating said hide with water at a pH of less than about 6.0 to leach out the sulfide, separating the hide from said leaching water, subjecting the treated hide to the action of the lining of an animal stomach in which peptic enzymes are normally elaborated, in the presence of water at a pH of from about 1.0 to about 2.5, until atleast part of the hide is brought into solution, neutralizing the resulting mixture, heating said mixture to destroy the enzyme and bring the remain: ing hide material into solution, and recovering hair from the said solution.

8. A process for recovering wool from sheep hide scraps which comprises subjecting said scrap to the action of hog stomach lining in the presence of water at a pH of from about 125 to about 1.9, at a temperature of from about 100 F.

to about 110 F., for about two days, adding sodium carbonate to neutralize the resulting mixture, heating said mixture to boiling, and separating the wool from the resulting solution.

9. A process for recovering wool from sheep hide containing sulfide and lime which comprises treating said hide with acidified water, the resulting mixture having a pH of from about 1.0 to about 3.0, to leach out the sulfides and lime, separating the hide from the leaching solution, subjecting said hide to the action of hog stomach lining in the presence of water at about pH 1.5, at a temperature 01' from about 100 F. to about 110 F., for about 36 hours, neutralizing the resulting mixture, heating said mixture to boiling, and separating the wool from the resulting solution:

10. A process for treating hide to recover hair therefrom which comprises subjecting said hide I to the action of the lining of an animal stomach in which peptic enzymes are normally elaborated in the presence of water at a pH oi. from about 1.0 to 2.5 until at least apart of the hide has gone into solution, neutralizing the resulting mixture,

. heating said mixture to dissolve any undissolved hide not already brought into solution by the action of said stomach lining, and removing hair from said solution.

VICTOR CONQUEST. HAYARD L. KEIL. 

